Intellectual functioning in children with early shunted posthemorrhagic hydrocephalus

Objectives: Early intervention for cognitive impairments seen in children with hydrocephalus is key to successful developmental outcome. Thus, the examination of the cognitive and behavioral functioning of children with hydrocephalus is important, given increasing survival rates and the potential to implement successful cognitive interventions. The current literature suggests that intellectual impairment is common in hydrocephalus patients, yet the findings vary concerning the extent and specifics of the cognitive deficits seen in these children. To better understand the pattern of cognitive impairment observed in children with shunted hydrocephalus, the present study examined a cohort of children with hydrocephalus uniformly shunted with a nonsiphoning valve in the first year of life. Methods: Forty-one children and adolescents with a history of congenital hydrocephalus, who were shunted with nonsiphoning valves in the first year of life and are currently achieving academically within 1 year of appropriate school grade for their chronological age, were compared to 16 nonaffected age- and education-level- matched controls. The subjects completed a comprehensive neuropsychological battery that included the Wechsler Intelligence Scale for Children, Third Edition, (WISC-III) as a measure of general intellectual functioning. Performances across the WISC-III were compared between the 2 groups. Results: The data were normally distributed for both groups. The children shunted for hydrocephalus scored approximately 1 standard deviation lower than the controls on the measures of general intellectual functioning (shunted group mean WISC-III full-scale intelligence quotient = 83.8 vs. control mean full-scale intelligence quotient = 102.9, p <= 0.001), verbal intellectual skill development [shunted group mean WISC-III verbal IQ (VIQ) = 86.6 vs. control mean VIQ = 107.1, p <= 0.001] and visuospatial and perceptual-organizational skill development [ shunted group mean WISC-III performance IQ ( PIQ) = 83.6 vs. control mean PIQ = 98.2; p <= 0.006]. History of shunt revisions, infections, prematurity, seizures and hemorrhage was not significantly correlated with intellectual functioning. While VIQ and PIQ have been reported as discrepant in many previous studies of cognitive functioning after shunting due to hydrocephalus, the current results revealed statistically similar VIQ/PIQ performance (Spearman's rho rank order r(s) = 0.685, p <= 0.001). Conclusions: Intellectual functioning in this selected group of children with hydrocephalus is normally distributed, yet significantly below that of nonaffected peers. Previously reported discrepancies between VIQ and PIQ were not evident in our study. This finding may be accounted for by the selectivity of our study population, implying a differential effect of etiology and treatment on intellectual function outcome in hydrocephalic children. Copyright (C) 2008 S. Karger AG, Basel.